Will the real Chimney Rock please stand up? [Photos]

President Barack Obama will officially designate Colorado's 4,700-acre Chimney Rock Archaeological Area as a national monument on Sept. 21. The designation is part of a two-year bipartisan effort to help preserve the site with assistance from the federal government and cooperation of the indigenous tribes that reside there.

The site possesses deep cultural significance to residents of the nearby Southern Ute Indian Reservation, whose ancestors watched lunar standstills occur between a pair of the stone pillars. Lunar standstills, which occur every 18.6 years, were considered spiritually significant for many ancient societies, including those that built famous megalithic monuments such as Stonehenge in England.

As interesting as this Chimney Rock is, it's not the only one that graces the landscape of the United States. Read on for more geologic oddities that share similar names and equally impressive features.

Towering nearly 300 feet above the surrounding North Platte River Valley in western Nebraska is the Chimney Rock National Historic Site.

The unusual, spindly rock formation was designated a historic site in 1956 due to its significance as a landmark along the Oregon Trail. The spire actually used to be much taller when it was first discovered by pioneers in the late 19th century, but its height has diminished since then due to erosion and lightning.

Although technically comprised of several buttes as well as numerous chimneys, Monument Valley is massive geological collection of dramatic sandstone formations located near the Arizona-Utah line. Carved by winding rivers over hundreds of millions of years, humans first began inhabiting the region as far back as 2,000 years ago.